Lifting jack



- 1,615 268 25 1927' F. L. GORMLE Y LIFTING JACK Filed Sept- 12, 1924 :s Sheets-Sheet 1 Rank L Ga .9:

by v J Jan 9 F. L. GORMLEY LIFTING JACK Filed Sept. 12 1924 3 Sheets-Sheet 2 liwenlor: E'anhL.Gor mZe Jan. 25 1927- F. L. GORMLEY V LIFTING JACK Filed Sep .12,

1924 3 Sheets-Sheet 5 Invchlvr: l'ranhLGormZe Patented Jan. 25, 1927.

UNITED" STATES 3mm; GonMnnY, or BBOOKLINE, MASSACHUSETTS.

LIF'IING JACK.

Application filed September 12, 1924. Serial No. 737,263.

This invention relates to lifting jacks and has for its object the production of a self lowering jack in which the working parts are reduced to a minimum and all back lash or lost motion is practically eliminated.

These objects are attained by the mechanism illustrated in the accompanying drawing.

For the purpose of illustrating the invention, one preferred formthereof is shown in the drawings, this form having been found to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which the invention consists canbe variously arranged and organized, and that the invention is not limited to the precise arrangement and organ- 'ization of the instrumentalities as herein shown and described, except as required by the scope of the appended claims.

Of the drawings:

Figure 1 represents a vertical section of a lifting jack embodying the principles of the present invention. a

Figure 2 represents a horizontal section on line 2, 2 on Fig. 1.

Figure 3 represents a rear elevation of the lower portion of the ack with the back plate removed.

Figure 4: represents an elevation of the inside of the back cover and the brake mechanism mounted thereon, and

Figure 5 represents an elevation of one side of the lower portion of said lifting jaclt Similar characters indicate like parts throughout the several figures of the drawings. i 1

In the drawings '10 is a base having an up- 'wa:rdly extending annular flange 11 threaded toan opening in the bottom of the standard 12 which has an upwardly extending cylindrical portion 12 'in which is mounted the ram 13, this portion 12 being entirely free of any lateral projections.

The ram 13 has a nut 14 positioned therein through which extends the threaded stem 15 of a revoluble gear 16 the teeth of which mesh with the teeth of a drivins gear 17 having a short shaft 18 positioned in a bushing 19 secured in the hub 20 extending laterally from the lower portion of the standard 12. d

When the base 10 is removed from the standard 12 the shaft 18 may be inserted in.-, to the bore of the hub 20, from the inner. end thereof and then the bushing 19 'is inserted into said bore from the outer end thereof.

Beneath the gear 16 is a bearing'plate 2 1 the periphery of which is provided with worm gear teeth 22 which mesh with a worm 69 23 secured to and revoluble with one end of a shaft 24 the opposite end of which has a gear 25 secured thereto.

YVithin the flange 11 of the base 10 is a ring 26 extending upwardly above said flange and within this ring is a bearing disk 27 resting upon the upper face of the base 10.

The disk 2? and plate 21 haveformed therein in opposed faces thereof annular 4 grooves in which are positioned antifriction members such the balls 28.

The load to be lifted is wholly supported by these antifriction members 28 and there is never any Strain upon the driving gear 17 or the retarding mechanism to be hereinafter described.

In the upper end of the ram 13 is positioned the flange 29 of a top plate 30 secured to said ram by a pin 81 so that said top platemay rotate with said ra n The ram may be rotated freely about the screw 15 until the top plate 30 comes into contact with the load to be lifted and then further rotation of the ram 13 will be prevented.

If the driving gear 17 is now rotated, causing the rotation of the screw 15 in the nut 14 the ram 13 will be moved upwardly in an obvious manner thereby lifting the load.

The gear 25 meshes with a pinion 32 secured to and revoluble with a ratchet 33 disposed within a recess in the clutch gear-34c revoluble about a hub on said ratchet 33, which ratchet is freely revoluble on the stud 35 fixed in the standard 10. a

The standard 12 is provided at the rear with a chamber 36 in which the retarding mechanism is positioned, thischamber being clo ed by a cover 37.

The cover 37 has a stud 38 extending inwardly therefrom on which is mounted a brake wheel 39 having secured thereto a pinion 40 the teeth of which mesh with the teeth of the clutch gear 34.

To the cover 37 are pivoted at 41 two brake arms 42 which are forced by'springs 43 into contact with the periphery of the brake wheel 39, these springs being powerful enough to prevent the rotation of said brake wheel when the arms 42 are in contact therewith.

Between the opposite ends of said arms 42 is a cam member 44 movable about a stud 45 by means of a finger piece 46 to separate the arms 42 sufficiently to permit the rotation of the brake wheel 39.

The clutch gear 34 has pivotally mounted therein a plurality of spring pressed pawls 47 which coact with the teeth of the ratchet 33.

When the ram 13 is being raised the worm gear 21 causes the worm 23 to be rotated thereby moving the ratchet 33 in the direction of the arrow at on 3 of the drawings.

As the clutch gear 34 at this time cannot move on account of the arms 42 being in frictional contact with the periphery of the brake wheel 39 it follows that the pawls 47 will ride over the ratchet teeth.

When the load has been lifted, the brake arms 42, being in contact with the brake wheel 39, will hold the load in elevated position until it is desired to lower the same.

In order to lower the load it is necessary for the operator to separate the arms 42 by manipulating the finger piece 46 and as soon as the frictional pressure on the brake wheel 39 is released, the ram 13 will commence to move downwardly, this movement causing the gear 16 to be rotated in a reverse direction and this reverse movement being imparted through the worm 23 and the train of gearing 25, 32, to the ratchet 33.

The teeth of said ratchet 33 will then engage the pawls 47, tending to move the clutch gear 34 about its axis, but this rotation of said clutch gear 34 may.be regulated by varying the frictional pressure of the arms 42 upon the brake wheel 39.

Obviously therefore the ram 13 maybe lowered at any desired speed by the simple manipulation of the finger piece 46.

'The clutch gear 34 is provided with a closing plate 48 which confines the ratchet 33 and pawls 47 within the recess in the said gear and prevents the admittance of any foreign substances intosaid recess to interfere with the proper working of the clutch.

Vhen the cover 37 is removed from the chamber 36 the brake wheel 39, arms 42 and pinion 40 will be removed therewith giving access to the clutch gear 34 and cam 44.

By removing the cover plate 48 access to the ratchet 33 and pawls 47 is obtained.

By this construction of jack all of the working parts are positioned near the base thereof, thereby making the jack very rigid and making it possible to make the parts heavier and more rigid than would be the case if these working parts were mounted near the top of the standard as in the latter case the jack would be liable to be top heavy.

Moreover the upper part of the jack is free from any projecting parts and as a consequence the jack can be used in many re stricted places where the ordinary self-lowering jack could not be used.

A lifting jack constructed as shown and described. herein has substantially no back lash or lost motion when the load is being lifted and in this respect is a great advance over the self-lowering jacks now in general use.

Furthermore, by such a construction of jack, seventy five and. one hundred ton acks may be made without the double set of gearing' now used while the entire jack is in very compact form.

Inasmuch as the entire bottom face of the gear 16 rests upon the bearing plate 21, there is no overhang of this gear and as a consequence a better support is given to this gear when lifting the load than is the case with the lifting jacks now in general use.

The pawls 47 are the full width of the ratchet 33 and consequently there is a more even bearing surface and better wearing of these parts insured.

Even if the cam member 44 is manipulated so as to fully separate the brake arms 42, the construction of the ack is Such that the ram is prevented from lowering at a dangerous speed by means of the retarding mechanism herein shown and described.

It is believed that the operation and many advantages of the invention will be apparent without further description.

Having thus described my invention, I claim- 1. In a self-lowering lifting jack, a standard having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; a gear on the lower end of said screw; a driving gear meshing therewith; a worm gear beneath said screw gear and ro tatable therewith; a worm meshing with and rotatable by said worm gear; a clutch gear within said chamber rotatable by said worm only during the lowering of the ram; and brake mechanism for retarding the rotation of said clutch gear during said lowering.

2. In a self-lowering lifting jack, a stand ard having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; a gear on the lower end of said screw; a driving gear meshing therewith; a worm gear beneath said screw gear and rotatable therewith; a worm meshing with and rotatableby said worm gear; a clutch gear withinsaid chamber; a ratchet rotatable about the axis of said clutch ear; pawls carrried by said clutch gear anc coacting with said ratchet only during the lowering of the load; means for rotating said ratchet actuated by the rotation of said worm; and brake mechanisnrfor retarding the rotation of said clutch gear during the lowering of the ram.

3. Ina selfdowering lifting jack, a standard having a chamber at oneside of its lower end; a ram reciprocablein said standard; a nut insaid ram';a rotatable screw in said nut; a gear on the lower end of saidscrew; a driving gear meshingtherewith; a worm gear beneath said screw gear and rotatable therewith;a worm meshing with and rotattble by said worm gear; a clutch gear within said chamber; a ratchet,rotatable-about the axis of said clutch gear; pawls carried by saidclutch gear and coacting with said ratchet only during the lowering of the load; means for rotating said-ratchet actuated by the rotation of said worm and including a. train of gearing; and brakemech anism for" retarding the rotation of said clutch gear during the lowering of the ram.

4. i In a self-lowering lifting jack, a stand ard'having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; a gear on the lower end of said screw; a driving gear meshing therewith; a worm gear beneath said screw gear and rotatable therewith; a worm meshing with and rotatable by said worm gear; a gear secured to the worm shaft; a pinion meshing therewith; a ratchet rotatable with said pinion; a clutch gear carrying pawls coacting with said ratchet only during the lowering of the load; a pinion meshing with said clutch gear; a brake wheel rotatable with the last mentioned pinion and about the axisv thereof; spring actuated brake arms coacting with said wheel; and means for releasing said arms from contact with said wheel,

5. In a self-lowering lifting jack a standard having a chamber at one side of its lower end; a ram reciprocable in said standard;

means for imparting reciproca-tory more 7 ment to said ram including a gear rotatable about the axis of said ram; a driving gear meshing with said rotatable gear; a worm gearb'eneath said rotatable gear and revoluble therewith; a worm meshing with and rotatable by said worm gear; a clutch gear within said chamber and rotatable by said worm only during the lowering of the ram; and brake mechanism for retarding the rotation of said clutch gear during said lowering. a

6. In a self-lowering lifting jack, a standard having a chamber at one side of its lower end; a ram reciprocable in said standard; means for imparting reciprocat'ory movementto said ram including a gear rotatable about the axis of said ram; adriving gear meshing with saidrotatable gear; a worm gear beneath said rotatable gear'and revolu ble therewith; a worm meshing with and rotatable-by said worm gear; a clutch gear within said chamber; a ratchet rotatable. about the axis of said clutchgear; pawls. carried by said clutch gear and coacting with said ratchet only during the lowering of the load; means for rotating said ratchet actuated by the rotation of said worm; and brake mechanism for retarding the rotation of said clutch gear during the lowering of the ram.

7. In I a self-lowering lifting jack, a standard having a chamber at one sideot its lower end; a ram reciprocable insaid standard; means for imparting reciproca-; tory movement to said ram including a gear rotatable about the axis of said ram; a driving gear meshing with said rotatable gear; a worm gear beneath said rotatable gear and revoluble therewith; a worm meshing with and rotatable by said worm gear; a clutch gear within said chamber; a ratchet rotatable about the axis of said clutch gear; pawls carried bysaid clutch gear'and coacting with said ratchet only during the lower-. ing of the load; means for rotating said ratchet actuated by the rotation of said worm and including a train of gearing;and brake mechanism for'retarding the rotation of said clutch gear during the lowering of the ram.

8. In a self-lowering lifting jack, a standard having a chamber at one side of its lower end; a ram reciprocable in said standard; means for imparting reciprocatory movement to said ram including a gear rotatable about the axis of said ram; a driving gear meshing with said rotatable gear; a worm gear beneath said rotatable gear and revoluble therewith; a worm meshing with and rotatable bysaid worm gear; a gear secured to the worm shaft; a pinion meshing therewith; a ratchet rotatable with said pin ion; a clutch gear within said chamber carrying pa-wls coacting with said ratchet only during the lowering of the load; a pinion meshing with said clutch gear; a brake wheel. rotatable with the last mentioned pinion and about the y axis thereof; spring actuated brake arms coacting with said wheel; and meanstfor releasing said arms from contact with said wheel. Y I v 9. In a self-lowering lifting jack, a standard having a chamber at one side of its lower end; a ram reciprocable in said standard; means for imparting reciprocatory movement to said ram including a gear rotatable. about the axis of said ram; 21 driving gear meshing with said rotatable gear; a worm gear beneath said rotatable gear and revoluble therewith; a worm meshing with and rotatable by said worm gear; a clutch gear within said chamber; a ratchet confined within said clutch gear; pawls carried by and within said clutch gear coacting with said atchet only during the lowering of the load; means for rotating said ratchet actuated by the rotation of said worm and including a train of gearing; and brake mechanism for retarding the rotation of said clutch gear during the lowering of the ram.

10. In a self-lowering lifting jack a standard having a chamber at one side of its lower end; a ram reciprocable in said standard; means for imparting reciprocatory movement to said ram including a gear rotatable about the axis of said ram; a driving gear meshing with said rotatable gear; a worm gear beneath said rotatable gear and revoluble therewith; a worm meshing with and rotatable by said worm gear; a gear secured to the worm shaft; a pinion meshing therewith; a ratchet rotatable with said pinion; a clutch gear within said chamber carrying pawls coacting with said ratchet only during the lowering of the load; a pinion i'neshing with said clutch gear; a brake wheel rotatable with the last mentioned pinion and about the aXis thereof; spring actuated brake arms coacting with said wheel; and a rotatable cam interposed between said arms for releasing said arms from contact with said wheel.

11. In a self-lowering lifting jack, :1 standard having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; means for rotating said screw; a worm gear secured to the lower end of said screw and rotatable therewith; a worm meshing with and rota-table by said worm gear, said worm being positioned between end walls of a recess formed in said standard and communicating with the interior chamber thereof; a shaft for said worm extending through bearings in said. end walls one end extending into said chamber; a gear on the extending end of said shaft; a ratchet adapted to be rotated from said gear; a clutch gear in said chamber rotatable about the axis of said pinion; pawls on said gear adapted to engage said ratchet only during the lowering of the load; and brake mechanism for retarding the rotation of said clutch gear during the lowering of the ram.

12. In a self-lowering lifting jack, a standard having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; means for rotating said screw; a worm gear secured to the lower end of said screw and rotatable therewith; a worm meshing with and rotatable by said worm gear; a ratchet within said chamber; means actuated by said worm for rotating said ratchet; a clutch gear having a recess to receive said ratchet; pawls onsaid gear engaging the teeth of said ratchet only during the lowering of the load; a plate secured to said clutch gear and closing said recess; and brake mechanism for retarding the rotation of said clutch gear during the lowering of the ram.

13. In a self-lowering lifting jack, a stand ard having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; means for rotating said screw; a worm gear secured to the lower end of said screw and rotatable therewith; a worm meshing with and rotatable by said worm gear; a ratchet within said chamber; means actuated by said worm for rotating said ratchet; a clutch gear having a recess to receive said ratchet; pawls on said gear engaging'the teeth of said ratchet only. during the lowering of the load; a plate to close said. chamber; a rotatable brake wheel mounted on the inner face of said plate; a pinion rotatable therewith and meshing with said'gear clutch; spring-pressed brake arms pivotally mounted on the inner face of said plate and normally contacting with said brake wheel; and means pivoted to said standard for moving said brake arms from contact with the brake wheel.

14. In a self-lowering lifting jack, va

. standard having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; means for rotating said screw; a worm gear secured to the lower end of said screw and rotatable therewith; a worm meshing with and rotatable by said worm gear; a ratchet within said chamber; means actuated by said worm for rotating said ratchet; a clutch gear having a recess to receive said ratchet; pawls on said gear engaging the teeth of said ratchet only during the lowering of the load; a plate to close said chamber; a rotatable brake wheel mounted on the inner face of said plate; a pinion rotatable therewith and meshing with said gear clutch; spring-pressed brake arms pivotally mounted on the inner faceof said plate and normally contacting with said brake wheel; and means pivoted to said standard and extending through said cover plate for moving said brake arms from contact with the brake wheel, said plate having formed thereon shoulders to limit the movement of said separating means about its axis;

15. In a self-lowering lifting jack, a standard having a chamber at one side of its lower end; a ram reciprocable in said standard; a nut in said ram; a rotatable screw in said nut; means for rotating said screw; a worm gear secured to the lower end of said screw and rotatable therewith; a worm meshing with and rotatable by said worm gear; a ratchet within said chamber; means actuated by said Worm for rotating said ratchet; clutch gear during the lowering of the ram,

a clutch gear having a recess to receive said all of said retarding devices being enclosed ratchet; pavvls on said gear engaging the in said chamber. 10 teeth of said ratchet only during the lower- Signed by me at 746 Old South Bldg, ing of the load; a plate secured to said clutch Boston, Mass, this 5th day of September, gear and closing said recess; and brake mech- 1924.

anism for retarding the rotation of said FRANK L. GORMLEY. 

